ShawN46
2019-09-12 18:27:50
- #1
Hello everyone,
I am using the following system:
- Viessmann Vitodens 200 gas condensing wall unit 19 kW
- Austria Email KWS 800 combined storage tank
- Solar flat plate collectors 9.36 m²
- ESR 31 solar control unit
- Delphis solar station FV 70 (with Grundfos circulation pump)
according to my heating technician, the whole system is equipped with heating support (before we discuss the usefulness, the system was already installed when we bought the house, everything installed at the end of 2015!)
In summer, I switched the Viessmann condensing wall unit to pure hot water operation, which, as far as I can tell, worked well. (Gas consumption between mid-June and early September was <1m³ natural gas)
At the end of last week, it got a bit cooler, so I gave in to my family’s requests and switched to hot water + heating. ;)
Now, I am a bit puzzled by how it works:
I set a target temperature of 22°C and today the outside temperature was 21°C (see picture 1!).
The heating curve is set to 0.8 (see picture 2!), based on which a flow temperature of 45°C should be generated at an outside temperature of approximately -5°C.
Under exactly these conditions, which were present today, the flow temperature at the pump station was 45°C! (see picture 3!):oops:
Of course, no circulation is occurring (supply and return were almost the same temperature), and the pipes just above the pump station could never have been 45°C, I would estimate a maximum of 30°C (by hand).
So why is the temperature of the heating circuit being pumped up that high? Is this normal and proper functionality?
From the roof at this time came approximately 57°C and the circulation pump of the solar system was running, temperature in the storage tank (bottom) just over 48°C. (In summer, with pure hot water operation and plenty of sun, sometimes >70°C in the tank, which, of course, was enough for a while despite large and regular water use for the paddling pool and water slide for the kids in the garden...)
Before I forget to mention: During the renovation, we had the system converted to a dry FHB system by Roth (previously normal radiators). From my layperson’s understanding, solar thermal support with heating should make more sense at the lower flow temperatures of underfloor heating than with traditional radiators and correspondingly higher flow temperatures?
Problem 1: The installer of the system was difficult to impossible to reach, now insolvent and also hard to understand...
Problem 2: My heating engineer has to understand a system he did not install, which apparently is an unusual configuration (The heating support is connected on the supply line and actually belongs on the return or vice versa, something was definitely weird, he said... but the function seems to be okay.)
I am well aware that I will not get around at least a consultation with my heating engineer, but I still hope that someone here can shed some light on my ignorance...
Thanks in advance for your effort!
Regards
I am using the following system:
- Viessmann Vitodens 200 gas condensing wall unit 19 kW
- Austria Email KWS 800 combined storage tank
- Solar flat plate collectors 9.36 m²
- ESR 31 solar control unit
- Delphis solar station FV 70 (with Grundfos circulation pump)
according to my heating technician, the whole system is equipped with heating support (before we discuss the usefulness, the system was already installed when we bought the house, everything installed at the end of 2015!)
In summer, I switched the Viessmann condensing wall unit to pure hot water operation, which, as far as I can tell, worked well. (Gas consumption between mid-June and early September was <1m³ natural gas)
At the end of last week, it got a bit cooler, so I gave in to my family’s requests and switched to hot water + heating. ;)
Now, I am a bit puzzled by how it works:
I set a target temperature of 22°C and today the outside temperature was 21°C (see picture 1!).
The heating curve is set to 0.8 (see picture 2!), based on which a flow temperature of 45°C should be generated at an outside temperature of approximately -5°C.
Under exactly these conditions, which were present today, the flow temperature at the pump station was 45°C! (see picture 3!):oops:
Of course, no circulation is occurring (supply and return were almost the same temperature), and the pipes just above the pump station could never have been 45°C, I would estimate a maximum of 30°C (by hand).
So why is the temperature of the heating circuit being pumped up that high? Is this normal and proper functionality?
From the roof at this time came approximately 57°C and the circulation pump of the solar system was running, temperature in the storage tank (bottom) just over 48°C. (In summer, with pure hot water operation and plenty of sun, sometimes >70°C in the tank, which, of course, was enough for a while despite large and regular water use for the paddling pool and water slide for the kids in the garden...)
Before I forget to mention: During the renovation, we had the system converted to a dry FHB system by Roth (previously normal radiators). From my layperson’s understanding, solar thermal support with heating should make more sense at the lower flow temperatures of underfloor heating than with traditional radiators and correspondingly higher flow temperatures?
Problem 1: The installer of the system was difficult to impossible to reach, now insolvent and also hard to understand...
Problem 2: My heating engineer has to understand a system he did not install, which apparently is an unusual configuration (The heating support is connected on the supply line and actually belongs on the return or vice versa, something was definitely weird, he said... but the function seems to be okay.)
I am well aware that I will not get around at least a consultation with my heating engineer, but I still hope that someone here can shed some light on my ignorance...
Thanks in advance for your effort!
Regards